Highly diastereoselective Friedel-Crafts reaction of indoles with an N-tert-butanesulfinylimino ester: an efficient and practical approach to enantiomerically enriched alpha-(3-indolyl)glycines.

An efficient, mild and general method for the preparation of highly enantiomerically enriched alpha-(3-indolyl)glycines by the transition-metal-based Lewis acid-catalyzed diastereoselective Friedel-Crafts reaction of indoles with an N-tert-butanesulfinylimino ester has been developed.